1. Field of the Invention
This invention relates to solder-bearing contacts and leads for attachment to contact pads on substrates such as electronic circuit boards, chip carriers, or the like.
2. Description of the Related Art
In the electronic equipment industry, it is known to provide leads for connection to contact pads of printed circuit boards and other substrates by soldering the leads thereto. See, e.g. U.S. Pat. Nos. 4,728,305 and 4,597,628. However, as the electronic industry continues to move toward greater miniaturization, the size and spacing between the contact pads has accordingly been reduced. This requires a corresponding reduction in the size and spacing of the leads which are to be connected to contact pads.
However, in attempting to reduce the spacing between leads, it is also important to provide sufficient spacing to prevent inadvertent contact or arcing between adjacent leads.
The objective of size/space reduction of the leads must be achieved without sacrificing accuracy in manufacture of the leads. It is also desirable to provide rapid assembly of multiple leads. Prior construction and manufacturing processes of leads have been unable to achieve effectively the required reduced size and spacing.
Thus, the need exists for effectively applicable leads of reduced size and spacing to accommodate the current reduction in the size and spacing of contact pads of substrates, but sufficiently spaced to prevent arcing. The need also exists for a method of manufacturing such leads without sacrificing accuracy.
In addition, in soldering a lead to a substrate contact pad, it has been common to provide solder between the lead and pad, either held on the lead or placed on the pad. When the solder liquifies, it forms a type of lubricant between the parts to be joined, which may be caused to vary their relative position, so that the parts may be misaligned when the solder solidifies.